2003 GMC Sierra 1500 Pickup Owner's Manual - Page 120

During the first 500 miles (805 km) of vehicle use, start the vehicle moving in FIRST (1) gear. This allows the clutch components to wear-in properly. FIRST (1): With the vehicle at a stop, release the brake, press the clutch pedai and shift into FIRST (1). Then, slowly let up on the clutch pedal as you press the accelerator pedal. Only downshift into FIRST (1) when the vehicle has come to a complete stop. If the shift lever will not go into FIRST (I), put the lever in NEUTRAL and let up on the clutch pedal to fully engage the clutch. Press the clutch pedal again. Then, shift into FIRST (1). SECOND (2): With the vehicle at a stop, release the brake, press the clutch pedal and shift into SECOND (2). Then, slowly let up on the clutch pedal as you press the accelerator pedal. Withthe vehicle moving, press the clutch pedal and upshift into SECOND (2) from FIRST (1) while applying light pressure to the right on the shifter. Then, slowly let up on the clutch pedal as you press the accelerator pedal. If you come to a complete stop and the shift lever will not go into SECOND (2), put the lever in NEUTRAL and let up on the clutch pedal to fully engage the clutch. Press the clutch pedal again. Then, shift into SECOND (2). THIRD ( ) Press the clutch pedal and upshift into 3: THIRD (3). Then, slowly let up on the clutch pedal as you press the accelerator pedal. FOURTH (4), FIFTH (5) and SIXTH (6): Upshift into the higher forward gears the same way as you do THIRD (3). Slowly let up on the clutch pedal as you press the accelerator pedal. NEUTRAL: Use this position when you start or idle your engine. REVERSE (R): To back up, press the clutch pedal. Wait for the vehicle to stop moving and then, shift to REVERSE (R). Let up on the clutch slowly while pressing the accelerator pedal. Also, use REVERSE (R), along with the parking brake, when turning off your engine and parking your vehicle. 2-33